The present embodiments relate to lightfield imaging. In medical imaging, the interior of a patient is scanned. Three-dimensional (3D) visualization is a common practice to assess and record the internal conditions of patients. The scan data is used to render an image of the patient. Interiors of other objects, whether represented by scan data or created as a model, may be imaged in non-medical environments. Images simulating a “fly-through” or from different viewpoints within the volume may be generated. The user may interact with the rendering to alter the location of the viewpoint, direction of viewing from the viewpoint, and/or rendering parameters.
In terms of high-performance rendering from the volume of a large amount of data, interactive or real-time rendering may be difficult. Volume rendering for highly realistic or ‘cinematic’ quality based on stochastic Monte-Carlo sampling of the volume requires a number of rays that cannot be handled easily, even by modern high-end graphics processing units. During interactive manipulation of the volume, like rotating or zooming, the user is presented with a rendering in progress. This incomplete rendering allows interaction. Due to the low number of rays that have been traced to allow interaction, the image contains rendering artifacts resulting in noisy images. Providing interactivity by sacrificing image quality is not desired.
Lightfield rendering solves the problem of interactivity with the compromise of requiring a huge amount of (compressible) data. However, lightfields have the disadvantage that allowable camera positions have to be outside the convex hull of the object or objects that are imaged. This precludes standard lightfield rendering from moving the camera into concave regions of the object, inside the object, or through the object, such as done for colonoscopy fly-through. The convex hull of the object captured in the lightfields occludes the interior.